Fixed bug #305: Scan with preferredPositionInResponse <= -2 crashes.

diff --git a/index/zrpn.c b/index/zrpn.c
index cea199f..8c8a258 100644 (file)
--- a/index/zrpn.c
+++ b/index/zrpn.c
@@ -1,4 +1,4 @@
-/* $Id: zrpn.c,v 1.141.2.8 2005-03-11 21:10:12 adam Exp $
+/* $Id: zrpn.c,v 1.141.2.9 2005-04-29 18:38:49 adam Exp $
    Copyright (C) 1995-2005
    Index Data Aps
 
@@ -2662,8 +2662,17 @@ void rpn_scan (ZebraHandle zh, ODR stream, Z_AttributesPlusTerm *zapt,
        return;
     }
     /* prepare dictionary scanning */
+    if (num < 1)
+    {
+       *num_entries = 0;
+       return;
+    }
     before = pos-1;
+    if (before < 0)
+       before = 0;
     after = 1+num-pos;
+    if (after < 0)
+       after = 0;
     scan_info_array = (struct scan_info *)
        odr_malloc (stream, ord_no * sizeof(*scan_info_array));
     for (i = 0; i < ord_no; i++)
@@ -2709,6 +2718,7 @@ void rpn_scan (ZebraHandle zh, ODR stream, Z_AttributesPlusTerm *zapt,
         const char *mterm = NULL;
         const char *tst;
         RSET rset;
+       int lo = i + pos-1; /* offset in result list */
         
         for (j = 0; j < ord_no; j++)
         {
@@ -2722,12 +2732,14 @@ void rpn_scan (ZebraHandle zh, ODR stream, Z_AttributesPlusTerm *zapt,
         }
         if (j0 == -1)
             break;
-        scan_term_untrans (zh, stream->mem, reg_id,
-                          &glist[i+before].term, mterm);
-        rset = rset_trunc (zh, &scan_info_array[j0].list[ptr[j0]].isam_p, 1,
-                          glist[i+before].term, strlen(glist[i+before].term),
-                          NULL, 0, zapt->term->which);
-
+       if (lo >= 0)
+       {
+           scan_term_untrans (zh, stream->mem, reg_id,
+                              &glist[lo].term, mterm);
+           rset = rset_trunc(zh, &scan_info_array[j0].list[ptr[j0]].isam_p, 1,
+                             glist[lo].term, strlen(glist[lo].term),
+                             NULL, 0, zapt->term->which);
+       }
         ptr[j0]++;
         for (j = j0+1; j<ord_no; j++)
         {
@@ -2735,40 +2747,46 @@ void rpn_scan (ZebraHandle zh, ODR stream, Z_AttributesPlusTerm *zapt,
                 (tst=scan_info_array[j].list[ptr[j]].term) &&
                 !strcmp (tst, mterm))
             {
-                rset_bool_parms bool_parms;
-                RSET rset2;
-
-                rset2 =
-                   rset_trunc (zh, &scan_info_array[j].list[ptr[j]].isam_p, 1,
-                              glist[i+before].term,
-                              strlen(glist[i+before].term), NULL, 0,
-                               zapt->term->which);
-
-                bool_parms.key_size = sizeof(struct it_key);
-                bool_parms.cmp = key_compare_it;
-               bool_parms.log_item = key_logdump_txt;
-               bool_parms.rset_l = rset;
-                bool_parms.rset_r = rset2;
-              
-                rset = rset_create (rset_kind_or, &bool_parms);
-
+               if (lo >= 0)
+               {
+                   rset_bool_parms bool_parms;
+                   RSET rset2;
+                   
+                   rset2 =
+                       rset_trunc(zh,
+                                  &scan_info_array[j].list[ptr[j]].isam_p, 1,
+                                  glist[lo].term,
+                                  strlen(glist[lo].term), NULL, 0,
+                                  zapt->term->which);
+                   
+                   bool_parms.key_size = sizeof(struct it_key);
+                   bool_parms.cmp = key_compare_it;
+                   bool_parms.log_item = key_logdump_txt;
+                   bool_parms.rset_l = rset;
+                   bool_parms.rset_r = rset2;
+                   
+                   rset = rset_create (rset_kind_or, &bool_parms);
+               }
                 ptr[j]++;
             }
         }
-        if (limit_set)
-        {
-            rset_bool_parms bool_parms;
-
-            bool_parms.key_size = sizeof(struct it_key);
-            bool_parms.cmp = key_compare_it;
-           bool_parms.log_item = key_logdump_txt;
-           bool_parms.rset_l = rset;
-            bool_parms.rset_r = rset_dup(limit_set);
-
-            rset = rset_create (rset_kind_and, &bool_parms);
-        }
-        count_set (rset, &glist[i+before].occurrences);
-        rset_delete (rset);
+       if (lo >= 0)
+       {
+           if (limit_set)
+           {
+               rset_bool_parms bool_parms;
+               
+               bool_parms.key_size = sizeof(struct it_key);
+               bool_parms.cmp = key_compare_it;
+               bool_parms.log_item = key_logdump_txt;
+               bool_parms.rset_l = rset;
+               bool_parms.rset_r = rset_dup(limit_set);
+               
+               rset = rset_create (rset_kind_and, &bool_parms);
+           }
+           count_set (rset, &glist[lo].occurrences);
+           rset_delete (rset);
+       }
     }
     if (i < after)
     {